| Vaccinium L., Ericaceae, the genus vaccinium spp, is a perennial defoliate or green-like shrub. It abrading, are found in north American, distribute the Northern Hemisphere, Antartic beach of American city and Southeast of Canada are discovered., and have more than 400 planting breeds. Vaccinium is distribute in the eastern, middle, southern, southwest and Northeast areas in China, appearing much on Knap and the areas of elevation 400-1400 meter. The fruit isblue-purple, sarcocarp is slender-greasy, grem is very small, the sapor is moderation and possess amenity fragrance. There peculiarly have blueberry anthocyanin which in their's fruit possess efficacy of improve eyesight, resist decrepitude and prevent cancer. It in praised "functionality and health protection berry in 21th century" and "queen of fruitage", also ranked the one of five healthy eatable about human being by International Food and Agricultural Organization(FAO). While blueberry is seen as a very promising emerge plant, the main problems of its development are of shallow roots without the larger main ones. These roots are either thin or underdeveloped with few hairs and small seeds and the limited growing regions caused by poor drought resistance. One of the efficient ways to change the situation is to combine the classical method of mutagenic breeding with marker-assisted selection (MAS), i.e., to induce and screen variations artificially so as to obtain the new blueberry germplasm resources with high yield, good quality and strong resistance.Currently most of the research on somaclonal variation of blueberry is still focused on direct regeneration system. The chemistry mutation changes the hereditary properties of the vegetative, because of it makes the DNA molecular construction suffered the harm, resulting duplicate mistake, consequently cause the gene mutation. So in order to increase the variety of somaclonal variatinon, the chemical mutagen is introduced; the useful variation and mutant with excellent characteristic are selected by using chemical mutagen under certain stress. In this study, we employed the means of combining the use of chemical mutagen and somaclonal variation, induced and selected the group of drought-resistant mutant in blueberry and pilot study was conducted on the group of mutant.Firstly, it focused establishment direct regeneration system of blueberry under the treatment of chemical mutagen. And the percentage of germination, the number of adventitious shoot, leaf length, leaf width and normal seedling of blueberry is counted. The results showed that the shoots of blueberry in 0.1%-0.6% EMS mortality rate of zero; concentration for inducing chilling resistant mutant in blueberry is 0.3%, with increased the average height of blueberry to 4.74cm (V3)or 4.52cm(3#); with increased the average area of blueberry to 1.173 cm2 (V3)or 1.073 cm2 (3#);significant difference. When the EMS concentration of 0.6%, its growth potential is weak, and for the upper part of small yellow-green, some leaves fall off.Secondly the paper is focused on the physiological mechanism of obtained chilling resistant mutant in blueberry. With the drought tolerance of some physiological indicators, and have selected may appear drought-resistant mutants EMS concentration.(1) Under drought stress, with stress time in the content of MDA was CK increase was most dramatic; contrast, the content of MDA was 0.1% and 0.5% increased slightly. The difference was not significant.(2) After EMS treatment, the soluble sugar content of regenerated plants were higher than control. The content of Soluble sugar was increased by 107.3% and 83.7%, when the treatment of 0.3% EMS for V3 and 3#. Difference was significant also.(3) After EMS treatment, the activity of SOD, POD of regenerated plants were higher than control. They were increased by 107.3% and 83.7%,188.73% and 142.8%, when the treatment of 0.3% EMS for V3 and 3#. Difference was significant also.(4) For V3, the activities of CAT of regenerated plants were higher than control, it was increased by 84.6%, when the treatment of 0.3% EMS. The activities of CAT of regenerated plants were less than control, when the treatment of 0.2% and 0.5% EMS. For 3#, the activities of CAT of regenerated plants were higher than control, they were increased by 48.72% and 62.15%, when the treatment of 0.13% and 0.6% EMS.Drought tolerant variants were selected from the MO generation plants, then the activity of SOD, CAT, POD enhanced and the content of MDA decreased which means that the regenerated plants' ability of drought resistant was improved. The strongest drought resistant mutant plants were obtained at the treatment of 0.3% EMS.Thirldly, the screening of phenotypic variant plants.From the 460 MO generations mutagenic plants, there were a total of 9 phenotypic variant plants to be screened out. The 9 variant plants were mainly varied in the morphological characteristics of whole leaves. The rate of phenotypic variation was very low, only 1.96%.In addition, we measured and analyzed 9 leaf anatomical structure indexes related to drought resistance of the 10 seedings, including stoma density, leaf thickness, top epidermis thickness, thickness of palisade tissue and so on. According to the result of multiple comparisons, we screened out 4 indexes with a high sense.According to the 4 indexes, an order of drought resistance of the 10 plants was given by using memberhip function values analysis:V-5>V-9>V-4>V-7>V-3>V-6>CK>V-1>V-2>V-4.
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